In order to test TLR4 signaling within the endothelium with reduced blood flow and impaired eNOS function, Yazji et al.4 evaluated the supplementation of the phosphodiesterase-5 inhibitor, sildenafil, in wild-type mice and observed a reduction in the severity of NEC, through vasodilation and maintenance of the intraluminal NO activity promoted by the substance4. The gene discussed is TLR4; the disease is necrotizing enterocolitis.